Thin and flexible light guide element

Abstract

The subject invention provides a thin and flexible light guide element, which comprises a first optical layer composed of a flexible transparent material; a second optical layer formed on the lower side of the first optical layer and having a light-adjusting structure to change the light path; and a third optical layer formed on the upper side of the first optical layer and having a convex-concave structure to homogenize the light emitted from the first optical layer, wherein the first and second optical layers have different refractive indices.

I claim: 
     
       1. A thin and flexible light guide element, comprising:
 a first optical layer composed of a flexible transparent material; 
 a second optical layer formed on the lower surface of the first optical layer and having a light-adjusting structure capable of changing the path of light, wherein the second optical layer is formed by coating a composition comprising at least one ultraviolet curing resin monomer and a photo initiator onto the first optical layer; and 
 a third optical layer formed on the upper surface of the first optical layer and having a convex-concave structure capable of homogenizing the light emitted from the first optical layer; 
 
       wherein the first and the second optical layers have different refractive indices. 
     
     
       2. The element as claimed in  claim 1 , wherein the difference between the refractive indices of the first and the second optical layers has an absolute value in the range from 0.001 to 0.6. 
     
     
       3. The element as claimed in  claim 1 , wherein the element has a thickness in the range from 30 μm to 350 μm. 
     
     
       4. The element as claimed in  claim 1 , wherein the flexible transparent material is a plastic substrate. 
     
     
       5. The element as claimed in  claim 4 , wherein the plastic substrate is selected from the group consisting of polyethylene terephthalate, and polycycloolefin resin, triacetate cellulose, and a mixture thereof. 
     
     
       6. The element as claimed in  claim 1 , wherein the light-adjusting structure has a form selected from the group consisting of a regular or irregular, continuously or non-continuously changing columnar structure, a conical structure, a solid angle structure, a lens structure, a wavy structure, and an arc-like block structure. 
     
     
       7. The element as claimed in  claim 6 , wherein the light-adjusting structure is a regular or irregular columnar structure. 
     
     
       8. The element as claimed in  claim 7 , wherein the columnar structure is a prism columnar structure or an arc-like columnar structure. 
     
     
       9. The element as claimed in  claim 6 , wherein the light-adjusting structure is an irregular prism columnar structure. 
     
     
       10. The element as claimed in  claim 9 , wherein the light-adjusting structure comprises a plurality of adjacent and non-parallel columnar structures. 
     
     
       11. The element as claimed in  claim 10 , wherein the columnar structures include linearly crossed prism columnar structures, linearly non-crossed prism columnar structures or both linearly crossed and non-crossed prism columnar structures. 
     
     
       12. The element as claimed in  claim 9 , wherein the prism has a vertex angle from 60° to 120°. 
     
     
       13. The element as claimed in  claim 11 , wherein the pitch between two crossed prism columnar structures is in the range from 0 and 100 μm. 
     
     
       14. The element as claimed in  claim 11 , wherein the pitch between two non-crossed prism columnar structures is in the range from 1 and 100 μm. 
     
     
       15. The element as claimed in  claim 1 , wherein the light-adjusting structure further comprises a metal material with a high reflectivity on the surface thereof. 
     
     
       16. The element as claimed in  claim 15 , wherein the metal material is silver or aluminum. 
     
     
       17. The element as claimed in  claim 1 , wherein the ultraviolet curing resin monomer is an acrylate monomer having one or more functional groups, a reactive monomer having an aromatic group, or a combination thereof. 
     
     
       18. The element as claimed in  claim 17 , wherein the acrylate monomer is a methacrylate or an acrylate. 
     
     
       19. The element as claimed in  claim 17 , wherein the acrylate monomer comprises 2-hydroxyethyl methacrylate, methyl methacrylate, butyl acrylate, and pentaerythritol triacrylate. 
     
     
       20. The element as claimed in  claim 17 , wherein the reactive monomer having an aromatic group is styrene, naphthylethylene, phenyl acrylate, or naphthyl acrylate. 
     
     
       21. The element as claimed in  claim 1 , wherein the composition further comprises inorganic particulates that have a particle size of 10 to 100 nm and are selected from the group consisting of titanium dioxide, zinc oxide, zirconium hydroxide, aluminum hydroxide, silicon dioxide, and a mixture thereof. 
     
     
       22. The element as claimed in  claim 1 , wherein the first and the third optical layers have different refractive indices and the absolute value of the refractive index difference is in the range from 0.001 to 0.6. 
     
     
       23. An LED backlight module comprising an element as claimed in  claim 1 . 
     
     
       24. A display device, comprising a backlight module comprising the thin and flexible light guide element as claimed in  claim 1  and an LED light source. 
     
     
       25. A thin and flexible light guide element, comprising:
 a first optical layer composed of a flexible transparent material; 
 a second optical layer formed on the lower surface of the first optical layer and having a light-adjusting structure capable of changing the path of light; and 
 a third optical layer formed on the upper surface of the first optical layer and having a convex-concave structure capable of homogenizing the light emitted from the first optical layer; 
 
       wherein the first and the second optical layers have different refractive indices and wherein the third optical layer has a surface resistivity in the range from 10 8  to 10 12 Ω/□; a haze in the range from 20% to 99% as measured according to the JIS K7136 standard method; and a pencil hardness of 3H or above as measured according to the JIS K5400 standard method. 
     
     
       26. A thin and flexible light guide element, comprising:
 a first optical layer composed of a flexible transparent material; 
 a second optical layer formed on the lower surface of the first optical layer and having a light-adjusting structure capable of changing the path of light; and 
 a third optical layer formed on the upper surface of the first optical layer and having a convex-concave structure capable of homogenizing the light emitted from the first optical layer; 
 
       wherein the first and the second optical layers have different refractive indices, and wherein the third optical layer is formed by coating a hard coat solution containing an anti-static agent, a UV curing resin, organic particles, and at least one resin selected from the group consisting of a thermal setting resin, a thermal plastic resin, and a mixture thereof onto the first optical layer. 
     
     
       27. The element as claimed in  claim 26 , wherein the anti-static agent is selected from ethoxy glycerin fatty acid esters, quaternary amine compounds, aliphatic amine derivatives, epoxy resins, siloxane, or alcohol derivatives. 
     
     
       28. The element as claimed in  claim 26 , wherein the UV curing resin comprises at least one resin of an acrylate monomer having one or more functional groups. 
     
     
       29. The element as claimed in  claim 28 , wherein the acrylate monomer is an acrylate or a methacrylate. 
     
     
       30. The element as claimed in  claim 28 , wherein the acrylate monomer comprises 2-hydroxyethyl methacrylate, methyl methacrylate, butyl acrylate, and pentaerythritol triacrylate. 
     
     
       31. The element as claimed in  claim 28 , wherein the UV curing resin further comprises a resin of an acrylate oligomer. 
     
     
       32. The element as claimed in  claim 26 , wherein the organic particles are selected from the group consisting of a methacrylate resin, a silicone resin, and a mixture thereof.